Known examples of electrochemical devices, which provide electrical energy through a chemical reaction or which cause a chemical reaction upon input of electrical energy, include various batteries and hydrogen production devices. Polymer electrolyte fuel cells (PEFCs), which are a type of electrochemical device, employ a polymer electrolyte membrane as an ion exchange part and have the advantages of being operable at lower temperatures than other types of fuel cells and having high output density. PEFCs are therefore highly expected to become widely used in the future. Conventional PEFCs are typically of the cation-exchange type employing a cation-exchange membrane that conducts hydrogen ions. However, in recent years, there have been an increasing number of reports of anion-exchange PEFCs employing an anion-exchange membrane, partly because anion-exchange PEFCs are capable of generating electricity without using a catalyst containing platinum which is expensive and the resources of which are scarce. Anion-exchange PEFCs use a liquid fuel (alkaline liquid fuel) such as hydrazine. The use of hydrazine as a fuel has a great advantage in that the fuel does not produce carbon dioxide (CO2), according to the electricity generation principle.
An anion-exchange polymer electrolyte fuel cell includes an anion-exchange membrane which is a polymer electrolyte membrane, a cathode catalyst layer, and an anode catalyst layer. Such a catalyst layer contains a resin having anionic conductivity and a catalyst. The resin contained in the catalyst layer serves to impart anionic conductivity to the catalyst layer and enhance the bond strength between the anion-exchange membrane and the catalyst layer. To allow a resin having an anion-exchange group to be uniformly distributed in a catalyst layer, a resin-containing liquid which is a solution or suspension of the resin in an organic solvent is used for formation of the catalyst layer. Thus, the resin having an anion-exchange group is required to be successfully dissolved or suspended in the solvent used in the resin-containing liquid and is particularly required to have high solubility in the solvent. For example, Patent Literature 1 discloses a resin having an anion-exchange group and having high solubility in organic solvents such as chloroform, THF (tetrahydrofuran), and 1-propanol.